Multifaceted protective helmets

ABSTRACT

In some embodiments, a protective helmet includes an outer shell including a sun visor, the outer shell comprising an outer surface having a plurality of non-parallel facets.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims priority to co-pending U.S. ProvisionalApplication Ser. No. 61/843,599, filed Jul. 8, 2013, which is herebyincorporated by reference herein in its entirety.

NOTICE OF GOVERNMENT-SPONSORED RESEARCH

This invention was made with Government support under grant or contractnumber W911NF-04-2-0018 awarded by the Army Research Laboratory. TheGovernment has certain rights in the invention.

BACKGROUND

Protective helmets are worn in many situations to protect the head frominjury that can result from impact with a static or dynamic object. Suchhelmets are often worn by players of various sports. For example,baseball players typically wear helmets when they are batting to protecttheir head from the pitched baseball.

While current protective helmets offer protection to the wearer,improvements in protection are always welcome because of the potentiallyserious nature of head injuries.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure may be better understood with reference to thefollowing figures. Matching reference numerals designate correspondingparts throughout the figures, which are not necessarily drawn to scale.

FIG. 1A is a top perspective view of a first embodiment of a facetedprotective helmet.

FIG. 1B is a front view of the protective helmet of FIG. 1A.

FIG. 2A is a top perspective view of a second embodiment of a facetedprotective helmet.

FIG. 2B is a side view of the protective helmet of FIG. 2A.

FIG. 3A is a side view of a third embodiment of a faceted protectivehelmet.

FIG. 3B is a top perspective view of the protective helmet of FIG. 3A.

FIG. 4 is a schematic view of a syntactic material that can be used toform an outer shell of a protective helmet.

DETAILED DESCRIPTION

Disclosed herein are protective helmets that offer improved protectionto the wearer. As described below, the helmets include faceted outersurfaces that reduce the potential for normal impacts and thereforedissipate energy that might otherwise be transmitted to the wearer'shead.

In the following disclosure, various specific embodiments are described.It is to be understood that those embodiments are exampleimplementations of the disclosed inventions and that alternativeembodiments are possible. All such embodiments are intended to fallwithin the scope of this disclosure.

FIGS. 1A and 1B illustrate a first embodiment of a protective helmet 10,which can be configured as a sports helmet. As shown in these figures,the helmet 10 generally comprises an outer shell 12 that is sized andconfigured to surround a wearer's head from the base of the skull to theforehead and from one ear to the other. In other words, the outer shell12 is sized and configured to surround all but the wearer's face. Thehelmet 10 can also include a relatively soft inner liner (not shown)that includes one or more flexible and/or resilient pads that providecushioning to the head and dissipate energy from impacts.

The outer shell 12 is generally rigid and can be made of any materialthat provides impact protection to the wearer. In some embodiments, theshell 12 is made of a polymeric material that is approximately 1 to 4 mmthick. The polymeric material that is used can depend upon theapplication of the helmet and the level of protection that is required.In some embodiments, the shell 12 is made of a long fiber thermoplastic(LFT) material. The use of LFTs is desirable because they provide highlevels of protection like continuous fiber reinforced composites but canbe processed using traditional plastics molding equipment. Therefore,parts can be manufactured at medium- to high-volume rates with excellentconsistency and repeatability. Long fibers (e.g., fiber lengths of about3 mm to 50 mm) provide an elastic modulus and a tensile strength that isup to approximately 80% of that obtained using continuous fibers.

In some embodiments, LFT materials are formed by hot melt-impregnatingcontinuous reinforcing fiber into a thermoplastic resin. The mixture canbe cooled and formed (e.g., chopped) into discontinuous reinforcingfiber pellets. The amount of thermoplastic resin can be approximately 50to 99 weight % of the LFT material and the amount of continuousreinforcing fiber (and once cut into the discontinuous reinforcingfiber) can be approximately 0.1 to 50 weight % of the LFT material.Example thermoplastic resins include polyamide, acrylonitrile butadienestyrene (ABS), polyphenylene sulfide, polypropylene, poly ether etherketone, poly ether ketone, polyethylene, poly butylene terephthalate,poly ethylene terephthalate, polyoxymethylene, and combinations(mixtures) thereof. Example reinforcing fibers include carbon, glass,aramid, polypropylene, polyethylene, basalt, poly{diimidazo pyridinylene(dihydroxy) phenylene}, natural fibers such as flax, kenaf, bamboo,jute, sisal, and combinations (mixtures) thereof.

In other embodiments, the outer shell 12 is made of a non-reinforcedpolymer material. Examples of such materials include polyamide, ABS,polyphenylene sulfide, polypropylene, poly ether ether ketone, polyether ketone, polyethylene, poly butylene terephthalate, poly ethyleneterephthalate, polyoxymethylene, or combinations (mixtures) thereof.

In still other embodiments, the outer shell 12 is made of a syntacticmaterial that comprises a plurality of microspheres (also referred to ascenospheres or microballoons) that are compounded with a thermoplasticresin. Such a material is schematically depicted in FIG. 4, which showsa syntactic material 90 that comprises microspheres 92 compounded with aresin 94. As is apparent from FIG. 4, the microspheres 92 are small,hollow spherical elements having an interior void 96 that is enclosed bya thin outer shell 98. Because much of the volume of the microspheres 92is void space (e.g., air), the microspheres and the syntactic material90 are very lightweight. By way of example, the syntactic material 90has a density of approximately 0.3 to 0.9 g/cc and the microspheres 92comprise approximately 30% to 35% of the material by volume percentage.In some embodiments, the microspheres 92 have a nominal outer diameterof approximately 0.1 mm to 1.0 mm and the shells 98 have a thickness ofapproximately 20 μm to 200 μm. The microsphere shells 98 can be made ofsubstantially any material that can be formed (e.g., blown) into a verysmall hollow sphere. By way of example, the microsphere's shells 98 canbe made of a polymeric, ceramic, glass, or metal material.

The resin 94 can comprise a polymeric resin. In some embodiments, theresin is a thermoplastic resin comprising an olefin, such aspolypropylene, polyethylene, or combinations (mixtures) thereof.Alternatively, the thermoplastic resin can comprise an engineeredpolymer, such as polyamide, polyether ether ketone (PEEK), polyetherketone (PEK), polyethyleneimine (PEI), polyphenylene sulfide (PPS), orcombinations (mixtures) thereof.

The protective helmet 10 can be used in substantially any context. Insome embodiments, the helmet 10 is used to protect the wearer's headduring sports activities. In the specific example illustrated in FIGS.1A and 1B, the helmet 10 takes the form of a baseball batting helmetthat includes one or more ear flaps 14 and a sun visor 16. It is notedthat, although a baseball helmet is shown in FIGS. 1A and 1B, the helmet10 could be configured for use in other sports, including football,hockey, lacrosse, field hockey, polo, bicycling, motorsports, and thelike. Moreover, the helmet 10 could be configured for non-sportsapplications, including military and combat applications.

Irrespective of its particular application, the outer surface 18 of theshell 12 comprises a plurality of facets 20 that lie in non-parallelplanes. In some embodiments, the facets 20 are generally planar (i.e.,not curved) and reduce the likelihood that a projectile will impact theshell 12 from a normal (perpendicular) direction. Accordingly, suchprojectiles will have the tendency to skirt or skip across the surface18 of the shell 12. In some embodiments, each facet 20 defines a similargeometric shape. In some embodiments, each facet 20 is triangular andtherefore includes three linear sides. In such cases, the triangles canhave three equal angles (equilateral triangle), two equal angles(isosceles triangle), or no equal angles (scalene triangle). In someembodiments, the groups of facets 20 define multifaceted prisms on thesurface 18 of the shell 12, such as the hexagonal, six-facet prism 22highlighted in FIG. 1A and/or the pentagonal five-facet prism 24highlighted in FIG. 1B. In both cases, the prism 22, 24 defines a raisedcentral point 26 that is formed by the corners of the facets 20 thatdefine the prism.

In some embodiments, each facet 20 has a nominal dimension ofapproximately 1 to 3 inches. In the example embodiment of FIGS. 1A and1B, in which the facets 20 are triangular, this dimension can be thelength of one or more sides of the triangles. In other embodiments, inwhich the facets are not triangular, the nominal dimension can be amaximum dimension (length or width) of the facet. By way of example, theouter surface 18 of the shell 12 can comprise approximately 80 to 150facets 20.

As shown in FIGS. 1A and 1B, the facets 20 can extend across much of theouter surface 18 of the shell 12 but not all of it. In the embodiment ofthese figures, the facets 20 do not extend to the ear flaps 14 or thesun visor 16.

With reference to FIG. 1A, the outer shell 12 also includes ventilationopenings 28 that enable air to reach the head and heat and vapor toescape the helmet 10. In some embodiments, the openings 28 areconfigured as elongated linear slits that extend along the length of thesides (edges) of two or more facets 20. In the example embodiment ofFIGS. 1A and 1B, the shell 12 includes four such openings 28 arranged ina spaced configuration near the top of the shell.

With further reference to FIG. 1A, the outer shell 12 also includes earopenings 30 that are formed in the ear flaps 14. In the illustratedembodiment, the ear openings 30 have a general teardrop shape in whichat least one edge of the openings 30 is curved.

FIGS. 2A and 2B illustrate a further embodiment of a protective helmet40. The helmet 40 is similar in many ways to the helmet 10 shown inFIGS. 1A and 1B. Therefore, the helmet 40 generally comprises an outershell 42 that can be made of one of the materials described above inrelation to the outer shell 12. The outer shell 42 includes ear flaps 44and a sun visor 46 and comprises an outer surface 48 that has aplurality of facets 50 that define multifaceted prisms 52 that eachincludes a raised central point 54 formed by the corners of the facets.The outer shell 42 further includes ventilation openings 56 and earopenings 58. Unlike the outer shell 12, however, the outer shell 40includes facets 50 that extend across the ear flaps 44. In addition, theear openings 58 are triangular instead of being teardrop shaped.

FIGS. 3A and 3B illustrate yet another embodiment of a protective helmet60. The helmet 50 is similar in many ways to the helmet 40 shown inFIGS. 2A and 2B. Therefore, the helmet 60 generally comprises an outershell 62 that can be made of one of the materials described above inrelation to the outer shell 12. The outer shell 62 includes ear flaps 64and a sun visor 66 and comprises an outer surface 68 that has aplurality of facets 70 that define multifaceted prisms 72 that eachincludes a raised central point 74 formed by the corners of the facets.The outer shell 62 further includes ventilation openings 76. Unlike thehelmet 40, however, openings 76 of the helmet 60 are arranged in analternative pattern in which six ventilation openings 28 are arranged inan “X” pattern that is visible from the top and rear of the helmet (seeFIG. 3B). The “X” pattern is formed by two crossed lines of openings 28,with each opening being arranged with its longitudinal axis aligned withits line. In addition, the helmet 60 includes facets 70 that extendacross the sun visor 66. Furthermore, the helmet 60 has an alternativeear opening pattern in which each ear flap 44 includes a first orprimary ear opening 78 and a second or secondary ear opening 80. In theillustrated embodiment, the first ear opening 78 is larger than thesecondary ear opening 80. In addition, the primary ear opening 78 istriangular while the secondary ear opening is elongated and linear.

In each of the above-described embodiments, the inner surface of theouter shell 12 can either be faceted in a similar manner to the outersurface 18 or can be smooth similar to conventional helmets. Regardless,it is reiterated that a relatively soft inner liner comprising one ormore flexible and/or resilient pads can be provided within the shell tocushion the wearer's head and/or dissipate direct or rotational force.

Claimed are:
 1. A protective helmet comprising: an outer shell includinga sun visor, the outer shell comprising an outer surface having aplurality of non-parallel facets.
 2. The helmet of claim 1, wherein thefacets are generally planar.
 3. The helmet of claim 2, wherein thefacets have a geometric shape.
 4. The helmet of claim 3, wherein thefacets are triangular.
 5. The helmet of claim 1, wherein groups offacets on the outer surface form multifaceted prisms having a raisedcenter point.
 6. The helmet of claim 5, wherein the prisms arepentagonal.
 7. The helmet of claim 5, wherein the prisms are hexagonal.8. The helmet of claim 1, wherein the facets have a nominal dimension ofapproximately 1 to 3 inches.
 9. The helmet of claim 1, wherein thefacets have a maximum dimension of 1 to 3 inches.
 10. The helmet ofclaim 1, wherein the outer shell further includes an ear flap.
 11. Thehelmet of claim 10, wherein the ear flap includes an ear opening. 12.The helmet of claim 1, wherein the outer shell further includesventilation openings.
 13. The helmet of claim 12, wherein at least oneventilation opening is formed along the sides of two adjacent facets.14. The helmet of claim 1, wherein the outer shell is made of apolymeric material.
 15. The helmet of claim 14, wherein the outer shellis made of a fiber-reinforced polymeric material.
 16. The helmet ofclaim 14, wherein the outer shell is made of a syntactic material thatincludes a plurality of microspheres.
 17. A baseball helmet comprising:an outer shell adapted to surround a wearer's head, the shell includingan ear flap that is adapted to cover an ear of the wearer and a visorthat is adapted to shield the wearer's eyes from light, wherein theshell comprises an outer surface having a plurality of non-parallel,planar, triangular facets, wherein groups of facets form multifacetedprisms on the outer surface having a raised center point.
 18. Thebaseball helmet of claim 17, wherein the prisms are pentagonal orhexagonal.
 19. The baseball helmet of claim 17, wherein the ear flapincludes an ear opening.
 20. The baseball helmet of claim 17, whereinthe outer shell further includes ventilation openings.